Sir Patrick Stewart's casting as Gurney Halleck was actually a mistake. Director David Lynch thought he had hired a different looking actor, as he had only seen Stewart wearing a costume and heavy makeup that made him look older in a play. This is the look the director was expecting, and when he showed up with his actual face, Lynch was disappointed at first.

Writer and director David Lynch has said he considers this movie the only real failure of his career. To this day, he refuses to talk about the production in great detail, and has refused numerous offers to work on a Special Edition DVD. Lynch had always claimed that revisiting the movie would be too painful an experience to endure. As of 2024, Lynch has clarified that a Director's Cut is impossible, as Dino De Laurentiis never allowed him to shoot scenes the way he wanted to or to take liberties with the source material Lynch felt he needed.

The suits worn by the Guild members were body bags that were found in a disused fire station dating back to the early 1920s. The bags had actually been used several times, something that was kept from the cast members until after shooting was completed.

Feyd-Rautha was originally to have stepped out of the "steam bath" nude. Sting had agreed to shoot the scene nude, but the studio panicked and told the costume designers that they had to put something on him. The skimpy winged G-string he wore was made almost at the very last minute before the scene was set to film.

At that time, Sir Patrick Stewart was completely unfamiliar about who Sting was as a musician. When meeting him on-set, he asked if he was a solo artist, to which Sting replied he was in a band called The Police. Totally unaware, Stewart thought Sting played in a police-band.

Continuity

Leto bites down on, and breaks, the false tooth, but it reappears in a subsequent shot.

Both, Duke Leto Atreides and his son Paul wear changing rank insignia on their dress uniforms. On planet Caladan, Paul wears an eagle, a star and a bar, as does his father and his friend Duncan Idaho, which makes no sense at all. During their space travel to Arrakis, Paul's epaulet sports an eagle and two stars, Leto's an eagle and three stars. This is logical, because the duke is one military rank above his heir. On Arrakis, the epaulets of their desert camouflage uniforms are the same as at the start of the movie.

When Paul is in the desert trying to ride the worm, the red coloring on the shoulders of the Feydakin are visible, but Stilgar did not mark the Fedaykin until before the Fremen started attacking the Spice harvesters, which happened after Paul had ridden the worm.

When Paul kills the Fremen in the knife fight in the cave, tears can be seen running down his face which is also covered in dirt. A few moments later his face is clean, but he hasn't had enough time to wipe all the dirt and tears away.

After Baron Harkonnen kills a young man in Giedi Prime, there is a head-shot showing Baron's face covered in black oil. Camera focuses briefly Feyd-Rautha (Sting) and then backs to the Baron, but his face is cleaner than before, and there is blood in the left side of his forehead.



Revealing mistakes

During the first battle of the film Rabban is seen throwing Atreides' conscripts off of a bridge. When Rabban throws a man off the bridge you can see the ground shake a few feet around the man as if he lands on some type of padding rather than solid ground.

In the morgue scene in Arrakeen, the establishing shot shows two Harkonnen corpses, one in the foreground and one in the background. The body in the background adjusts his head to find a more comfortable position.

Stars visible through planets in several scenes.

When Feyd-Rautha is carrying the cat and accompanying the Baron down the stairs, you can see a few glimpses of the two fishing lines helping the Baron fly.

During shield practice, when Gurney slides across the floor, the face of Patrick Stewart's stunt double can be seen. Kyle MacLachlan's stunt double can also be seen when Paul slowly pushes his knife through his shield.



Miscellaneous

The closing credits include a typographical error, where 4 "Administrative Staff" are described as "Admistrative Staff".



Character error

At 1 hour 28 minutes and 40 seconds, Paul is seen standing next to Chani his eyes are blue, in the next scene Paul's eyes are normal. At this point in the movie Paul has only been on the planet Dune for a few days, it takes years of extended exposure to the spice for one’s eyes to become blue, like the Fremen, which happens to Paul later in the movie.

When Stilgar marks the Fedaykin shoulders with red paint, blood, he says there are 15 of them. Right before Paul takes the water of life, freeze frame and you will see 16 of them.